First off, going higher in elevation would have made the bike richer, not leaner. You need to decide what size pistons are in it before you buy new. You will want to have the cylds bored to the next size if they are good or maybe even 2 sizes if they are way out of round or scared real bad. The weisco pistons won't come with bearings so you will need to order those separate. You are best off to send the cylds to a site sponsor to get bored so you know they are done right and buy your pistons, gasket, etc. From them. Support those who support the sport, NOT EBAY!